From 1c5c12ee308aacf635c8819cd4baa3bd58f8a8b7 Mon Sep 17 00:00:00 2001 From: Tao Ren Date: Wed, 24 Apr 2019 01:43:32 +0000 Subject: net/ncsi: handle overflow when incrementing mac address Previously BMC's MAC address is calculated by simply adding 1 to the last byte of network controller's MAC address, and it produces incorrect result when network controller's MAC address ends with 0xFF. The problem can be fixed by calling eth_addr_inc() function to increment MAC address; besides, the MAC address is also validated before assigning to BMC. Fixes: cb10c7c0dfd9 ("net/ncsi: Add NCSI Broadcom OEM command") Signed-off-by: Tao Ren Acked-by: Jakub Kicinski Acked-by: Samuel Mendoza-Jonas Signed-off-by: David S. Miller --- include/linux/etherdevice.h | 12 ++++++++++++ net/ncsi/ncsi-rsp.c | 6 +++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index e2f3b21cd72a..aa8bfd6f738c 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -448,6 +448,18 @@ static inline void eth_addr_dec(u8 *addr) u64_to_ether_addr(u, addr); } +/** + * eth_addr_inc() - Increment the given MAC address. + * @addr: Pointer to a six-byte array containing Ethernet address to increment. + */ +static inline void eth_addr_inc(u8 *addr) +{ + u64 u = ether_addr_to_u64(addr); + + u++; + u64_to_ether_addr(u, addr); +} + /** * is_etherdev_addr - Tell if given Ethernet address belongs to the device. * @dev: Pointer to a device structure diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c index dc07fcc7938e..802db01e3075 100644 --- a/net/ncsi/ncsi-rsp.c +++ b/net/ncsi/ncsi-rsp.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -667,7 +668,10 @@ static int ncsi_rsp_handler_oem_bcm_gma(struct ncsi_request *nr) ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE; memcpy(saddr.sa_data, &rsp->data[BCM_MAC_ADDR_OFFSET], ETH_ALEN); /* Increase mac address by 1 for BMC's address */ - saddr.sa_data[ETH_ALEN - 1]++; + eth_addr_inc((u8 *)saddr.sa_data); + if (!is_valid_ether_addr((const u8 *)saddr.sa_data)) + return -ENXIO; + ret = ops->ndo_set_mac_address(ndev, &saddr); if (ret < 0) netdev_warn(ndev, "NCSI: 'Writing mac address to device failed\n"); -- cgit v1.2.3-59-g8ed1b